This invention relates to devices by which a medicament can be administered to or by patients inhaling through the devices. The medicaments may be in solid finely divided form or fluid form. Such devices are now quite well known for administering medicaments contained in capsules to patients suffering from bronchial conditions such as, for exammple, bronchial asthma. It is well known for medicament in powder or other finely divided form to be supplied in capsules which are loaded by a patient into such a device which is sometimes called an "insufflator". The medicament is then released from the capsule and inhaled by the patient, usually through the mouth, but sometimes through the nose.
The specification of PCT Application Publication No. WO82/01470 and U.K. Patent Specification No. 1387954 both describe devices for dispensing medicament in finely divided form from capsules. In each of these previously described devices, the capsules are mounted on a rotatable support member on which each capsule in turn can be brought to a position in which it is opened to enable medicament to exit from the capsule to permit it to be inhaled by a patient inhaling through a mouthpiece of the device. In the device described in U.K. Specification No. 1387954, the capsules may be mounted in a so-called blister pack.
There are disadvantages in the use of capsules, which are made of gelatin, to contain medicaments. Gelatin is relatively unstable and is lacking in physical strength so that the capsules need to be protected by packaging, for example in glass bottles. Environmental degradation of both the capsules and their contents may occur in a relatively short time.
An object of the present invention is to provide a more convenient way of administering medicament to such patients than has been possible hitherto and which avoids the need to pack medicaments in capsules. The device of the present invention makes use of the technique of packing medicaments by loading them in blister packs, that is to say, packs comprising a sheet, which may be laminated, of foil or plastics material which acts as a carrier and which is provided with a number of breakable or openable containers called "blisters" incorporating a sheet secured on a first sheet to form a cover or lid. Such blister packs are in common use with tablets of one kind or another, but we have discovered that they can also be used with medicaments in finely divided solid form or in liquid form.